Delphinapterus leucas

Delphinapterus leucas (Pallas, 1776) —Beluga, white whale

Delphinus leucas Pallas, 1776 p.85; Type locality- Mouth of Ob River, Northeast Siberia.

Delphinapterus catodon: True, 1884 p.590.

Delphinapterus leucas: Kuroda, 1938 p.14; Kim et al., 2000 p.74; Kim, 2004 p.231.

Range: The beluga is common in the Sea of Okhotsk but very rare in the waters of Korea. Since it was observed migrating along the southeastern coast near Busan (southeastern tip of the Korean Peninsula) in August of 1997, the range is expected to reach the southern waters of the East Sea (Kim 2004; Fig. 90).

Remarks: The genetic structure of the mtDNA control region of the beluga whale in the Russian Far East down into the East Sea indicated a high degree of philopatry (Meschersky et al. 2013). Some populations became genetically isolated from those of the Sea of Okhotsk; whereas, they share a common gene pool (Meschersky et al. 2013). Allelic frequencies at nine microsatellite loci had a mean genetic diversity of 0.69 that increased from north to south with the highest value in the south (Meschersky et al. 2013). The high level of haplotypic and nucleotide diversity and the presence of a set of unique haplotypes in beluga whales suggests that their ancestors lived and bred in the southern Sea of Okhotsk or in the East Sea of Korea during a time span that includes the pre-Holocene epoch. This area probably served as the refugium from which animals dispersed northward (Meschersky et al. 2013). Despite geographic variation in size and DNA, D. leucas is considered a monotypic species.